Scavenging of Extracellular H2O2 by Catalase Inhibits the Proliferation of HER-2/Neu-transformed Rat-1 Fibroblasts through the Induction of a Stress Response*

High levels of reactive oxygen species (ROS) are associated with cytotoxicity. Alternatively, nontoxic levels of ROS like hydrogen peroxide (H(2)O(2)) can mediate the transmission of many intracellular signals, including those involved in growth and transformation. To identify pathways downstream of endogenous cellular H(2)O(2) production, the response of Rat-1 fibroblasts exhibiting differential HER-2/Neu receptor tyrosine kinase activity to …